Used in the treatment of various cancers, particularly advanced solid tumors such as hepatocellular carcinoma and non-small cell lung cancer. It functions by blocking the CTLA-4 receptor on T-cells, enhancing immune system activation against cancer cells. Often used in combination with other immunotherapies like anti-PD-1/PD-L1 antibodies to improve antitumor response. Currently investigated in clinical trials for use in melanoma, mesothelioma, and other malignancies where immune modulation plays a key role.